Device for removing curvature from metallizing wires



y 1943. A. P. SHEPARD 2,318,019

DEVICE FOR REMOVING CURVATURE FROM METALLIZING WIRES Filed April 10,1941 2 Sheets-Sheet l 9 a ll/v, z

i a v n I A INVENTOR: Arfizur f? Shepard A BY a u i ATTORNEY y 1943- A.P. SHEPARD 2,318,019

DEVICE FOR REMOVING CURVATURE FROM METALLIZING WIRES Filed April 10,1941 2 Sheets-Sheet 2 INVENTOR liiTORNE Patented May 4, 1943 2,318,019DEVICE FOR REMOVING CURVATURE FROM METALLIZING WIRES Arthur P. Shepard,Forest Hills, N. Y., assignor to Metallizing Engineering Company, Inc.,Long Island City, N.

Y., a corporation of New Jersey Application April 10, 1941, Serial No.387,812 Claims. (01. 140-148) This invention relates to new and usefulimprovements in a device for removing curvature from a metallizing wire.

Metal spray guns are commonly equipped with a mechanism -for feedingmetal in the form of slender rods or wire into the gun thence through aheating zone where the metal is melted, and finally into an atomizingzone where the molten metal is atomized by a blast of air or other gasand from which the atomizing metal is propelled in the form of a finelydivided metal spray. Metal spray guns are often used forhand work, theyare usually of a light construction and the amount of power availablefor feeding the metal rods or wire is considerably limited. The metalused for spraying is most commonly supplied in the form of wire woundinto coils for convenience in handling. The coils are usually placed ona reel so that the wire can unwind from the coil as it is fed into themetallizing gun. This practice, however, has one serious disadvantage,for the wire unwinds from the coil retains a permanent set or curvaturewhich causes considerable difiiculty in the successful operation of thespray gun. This difiiculty is primarily of two kinds. First,interference of the curvature of the wire with the wire feedingmechanism of the metal spray gun, and second, interference of thecurvature of the wire with the proper centering of the same in theheating zone.

Interference of the curvature of the wire with the feeding mechanism ofthe metal spray gun is serious because in some cases it causes prematurewear and damage .to the mechanism, as the result of the excess dragimposed upon the mechanism by the curvature of the wire which isparticularly bad where large wires of hard materialsuch as 4;" diameterwires of nickel, carbon steel, stainless steel, etc., are used. In somecases the drag due to such curvature is so great that it slows down themechanism and the proper feeding speed cannot be obtained. The majortrouble with the mechanism is in most cases encountered, however, as theresult of fluctuations in the feeding speed caused by the curvature ofthe wire. Furthermore, the wire tends to flop around as it feeds intothe gun thereby continually varying the drag on the Wire feed mechanism..This in turn varying atomizing condition spray at times fine and at antupon the speed of the Wire. metal coats, however, are in most casesundesirable. Inasmuch as the spray gun tends to spray a coarse coat whenthe wire feeds too fast,

so that the gun will Coarse spray causes a continually times coarsedependit is generally the practice of the operator to slow the gun downto such extent that coarse spraying is avoided even though the wiresurges ahead at times. Such practice, however, causes an average wirespeed of far less than could be obtained with a steady feed and henceresults in loss of time and money.

Even if the metallizing gun feeds the wire with a comparatively steadyfeed, coiled wire still causes the second type of difliculty mentionedabove, as the result of improper centering of'the tip of the wire in theheating or melting zone. The melting zone is usually a small cone ofintense heat such as would be produced by an oxygen/acetylene flame, themost intense heat being at the center of the cone. The wire extends intothis melting zone and should be centered as accurately as possible wasto take advantage of the more intense heat in the center. When the wirehas a curvature, it tends to run off to the side of the zone, hencerequiring reduced spraying speed with loss of time and money, due to aslower rate of melting. In addition to this trouble, the wire tends tomelt off somewhat crooked when it is not in the center of the meltingzone and hence it is not evenly atomized by the blast of atomizing gas,so that a coarse or spattering type of spray results.

The above described difficulties and drawbacks inherent in the use ofcoiled metal spray I wire are considered so serious by many operators inthe metallizing industry that the practice developed by using straightrods instead of coiled wire. Straight rods overcome the above describeddisadvantages of coiled wire, and make it possible to increase sprayingspeeds and produce finer, more uniform, atomization of the metal. Theuse of straight rods, however, has been found to be impractical, exceptin very limited cases because of the difficulty of handling a sufficientquantity of metal in the form of rods without continued interruption ofthe spraying operation. The maximum practical lengths for rods which canbe handled conveniently is from 12 to 20 feet long and even these cannotbe handled as conveniently as coiled wire. Each time a rod has fedthrough the gun, another rod must be inserted in its place, but eachtime this is done, a small piece of rod is wasted, as the end or remnantof the'flnished rod blows out of the end of the gun without beingmelted. This requires that either the gun be stopped or that a shutteror damper be placed in front of the gun to prevent this remnant of rodfrom splattering on the work being sprayed.

hence throw the wire from the same.

There have been wire straightening devices known in the past for thesolution of other wire straightening problems, but none has as yet beenknown which can solve this particular problem. Most wire straighteningdevices are adapted for removing kinks from wires with the result thatthey require considerable energy to draw the wire through them. Theremoving of kinks is not a problem in metal spraying as wire which isentirely free of kinks is easily obtainable for metallizing purposes.For the purpose of straightening wire for metallizing, attemptshave beenmade to pull the wire through a series of rollers which are so locatedas to bend the wire back and forth several times in an attempt tostraighten it. Such methods have been unsuccessful because bending thewire several times requires too much energy and imposes too much drag onthe wires, as it enters the metallizing gun.

The device in accordance with the invention for removing curvature inmetallizing wire, due to the coiling of such wire, overcomes all of thetroubles caused by coiled wire and retains all of the advantages andconvenience of using coiled wire for metallizing work. This device byits special construction removes the curvature from the wire due tocoiling thereof and require a minimum of pull or drag on the wire to dso. In fact, the pull required is so slight that the actual work by thedriving mechanism of the metallizing gun is reduced more by thestraightness of the wire as it goes through the gun, than it isincreased by the energy required in the curvature removing operation ofthe device.

The wire curvature removing device, in accordance with this inventionwill be more fully understood from the following description read inconjunction with the drawings in which:

Fig. 1 is a perspective view of the device shown with the coiled wire inthe operating position.

Fig. 2 is a top view of the device.

Fig. 3 is a section taken through the plane III-III in the showing ofFig. 2.

Fig. 4 is a section taken through a part of the device through the planeIVIV in the showing of Fig. 2.

Fig. 5 shows a top view of the device with a different arrangement ofparts than that shown in Fig. 2.

As illustrated in the drawings a mounting base preferably on legs 2carrie at one end wire reel 3, upon which rests the coiled metallizingwire 4. Wire reel 3 has a rotating top 4a mounted on a stationary base5. .5 ball bearing (not shown) is preferably utilized as a Divot in thecenter between stationary base 5 and rotating top 4a of the wire reel 3.A friction or brake member (not shown) is preferably provided betweenmembers 40 and 5 to exert a slight amount of friction opposing therotation of member 4a. This is sometimes desirable with springy wire asit prevents the uncoiling of the wire. The reel 3 is preferably soconstructed that it rotates as freely as possible, and yet not so freelythat the springiness of the wire will unwind the reel and Reel top 40.may be provided with extension cros arms 8. as for instance shown inFig. 1 to permit using large coils of wire or it may be used withoutsuch cross arms, as shown in Figs. 2 and 5, where small coils of wireare being used.

The pins 1 are inserted into the cross s 5 to locate the coiled wirewhen large coils are used, or the sac e pins 1 may be inserted directlyInto the wire reel top 4a when small coils of wire are used.

The curvature removing head assembly 8 is preferably mounted on base Iopposite the wire reel. Bracket 9 mounted on base I is of such height asto locate the top of the head assembly at the approximate level at whichthe wire unwinds from reel 3. Through the upper end of bracket 9 extendsa flat head cap screw I0, which is fastened on the underside by a nutII. This cap screw and nut serve to secure the bracket to the two platesI2 and I3, the plate l3 being under the plate l2. The flat head of the'cap screw I8 is secured to the plate I2 by means of two small pins I4which prevent the head from rotating and make it easy to loosen ortighten the cap screw by simply turning the nut II, which is underneath.The plate I3 is turned at an angle with respect to plate I2 and in thespecific embodiment of the invention shown in this illustration, theangle between their axes is approximately degrees. To locate the angleof plate I3 with respect to plate I2, and to locate plate I2 properlywith respect to the bracket 9, a hole may be provided in each of thesemembers I2, I3 and 9 so that these three holes line up when the threemembers are in the proper location in respect to each other. These holesin plates I2 and I3 are clearance holes for screw l5 and the hole inplate 9 is a tapped hole to fit the threads on screw l5. Therefore, whenscrew I5 is inserted through the holes in plates I2 and I3, and screwedinto the hole in bracket 9, the relative location of the three membersis fixed. At the other end of plate I2 a plate I6 is pivotally fastenedby means of flat head cap screw I1 and nut I8 which is underneath. PlateI6 is underneath plate I2. The head of cap screw I1 is fastened to plateI2 by means of two pins I8, which prevent the rotation of the head ofthe cap screw and make it convenient to loosen -or tighten the screw bysimply turning the nut |8 underneath. Washers 20 are provided for bothnut |8 andnut II.

Extending from and fastened to plate I3 are two strips 2|. On the endsof these two strips 2| are mounted the small right angle bracket pieces22, 23, 24 and 25. These pieces are clamped together and to the strips2| by the two screws 28, and between the brackets as shown in Fig. 4 areclamped the ball bearings 21 and 28. Ball bearings 29 and 38 are clampedbetween the bracket pieces by screws 3|. Washers 32 are provided on eachside of each bearing to provide the properspacing and to permit all ofthe bearings to rotate freely even though they are clamped on the innerraces. This arrangement of the four ball bearings 21, 28, 29 and 30provides a ball bearing wire guide orifice through which passes the wire4. The ball bearings are spaced so that they do not quite touch eachother and yet are set close enough to each other to retain the wirewithin the orifice.

On the front end of plate I6 two ball bearing wheels 33 and 38 withchanneled rims are mounted and held in place by the two screws 35 andnuts 36. Cupped shaped washers 31 are mounted one each on top of theball bearing wheels under the screw heads to act as dust shields for thebearings. Block 38 is placed on top of plate I5 and under the bearings33 and 34 so as to locate the bearings at the proper height. Thisarrangement of the ball bearing wheels 33 and 34 provides a wire guidebetween the wheel rims, so

that the wire 4 can pass through the guide space defined by the wheelrims as shown in Fig. 3.

Ball bearing channeled wheels 39, 40, 4| and 42 are mounted on plate I2in pairs as shown. The mounting of these bearing wheels is similar tothat described for bearing wheels 33 and 34, they being fastened to theplate by screws and shielded by cupwashers 31. However, in the case ofthe ball bearing wheels 39, 40, 4| and 42, no block such as block 38 isprovided as the wheels are of the proper height when mounted directly onto plate I2.

The relative location of the various ball bearings and ball bearingwheels is important. The location of the wire reel 3 with respect tothese ball bearing wheels and ball bearings is also important. First itis essential that the centers of the wire guiding spaces between theball bearing wheels 33, 34, and 39, and 4|, 42 and 21, 28 be all inapproximately the same plane and in approximately the same plane as thatin which the wire unreels from the coil of wire 4 resting on wire reel3. Second, it is essential that the path of travel of the wire definedby the pairs of ball bearing wheels 21, 28 and 4|, 42 and 39, 40 befixed in substantially the same plane on a curve which approximates thecurvature of the wire as it leaves the wire reel. The wire reel ispreferably so located with respect to the wire guiding spaces of theselast mentioned three sets of ball bearing wheels, that the wire leavingthe wire reel is fed to the pair of guide wheels 21, 28 in substantiallyits natural curvature and thereafter continues in its path of travel atapproxi mately the same curvature through the two guiding spaces betweenthe two pairs of wire guiding wheels aforementioned 21, 28 and 4|, 42respectively. Third, it is essential that the path of travel of the wiredefined by the wire guiding spaces between the pairs of ball bearingwheels 33, 34; 39, 40; 4|, 42 is fixed in a substantiallyeountercurvature direction in substantially the same plane at an angleor curve sufllcient to straighten the wire.

In operation the wire 4 is drawn from between the ball bearing wheels 33and 34, by the feed mechanism in the metallizing gun, and the wireemerges from between these two ball bearing wheels with the curvatureremoved. The wire coiled on reel 3 unwinds from the reel assuming thecurvature due to the coiling thereof. It feeds to and through theorifice defined by the ball bearing wheels 21, 2B, 29 and 30. From thesewheels it continues to maintain approximately its curvature until itpasses between the two ball bearing wheels 4| and 42. This arrangementof Wheels and their location with respect to the wire reel locates thewire 4 positively in the plane of its curvature so that it cannot rotatefrom this plane. This makes it possible for the two sets of ball bearingwheels 33, 34; 39, 40, to act on the wire in a single plane and to bendit in the opposite direction from its curvature and in the same plane asits curvature. The curvature in the wire is thereby removed by a singlebending action produced by the last two sets of rollers so that the wireemerges from the device as straight wire. No unnecessary bending orgripping of the wire is required and the curvature is thus removed withthe least possible expenditure of energy.

It is obvious from the foregoing that the head assembly 8 must be inproper location with respect to the wirereel 3, and that the device willvided in plate not operate'properly unless this relationship asdescribed above is maintained.

The device as illustrated in Fig. 2 is arranged to operate with wirecoiled so as to unwind from the coil when the wire reel turnscounterclockwise as 'viewed from the top. Sometimes the wire coils arewound in the reverse direction, so that it is desirable to unwind thewire from the coil as the reel turns clockwise as viewed from the top.Therefore, provision has been made for reversing the arrangement of theplates I6, I2 and I3 as shown in Fig. 5. To facilitate ready andaccurate locationof the relative position of plates I2 and I3, anadditional hole 43 may be provided in plate I2 and an additional hole 44may be pro- I3. When the plates I2 and I3 the reverse position as shownIn 43 and 44 line up with the tapped have assumed Fig. 5 holes hole inbracket 9 at I5, so that screw I5 may be used to lock them in position.Therefore, to reverse the position of the head assembly 8 for the use ofoppositely coiled wire it is only necessary to loosen nut II, removescrew I5, swing the plates around to the new position about the centerof cap screw III, replace screw I5 through holes 43 and 44 and into thetapped hole in bracket 9, re-tighten nut II, loosen nut I8, and finallyreverse the angle of plate IB'with respect to plate I2 and tighten nutI8.

It has been found that it is usually possiblefor commercial sizes ofwire and commercial sizes of coils, to predetermine the angle betweenplate I3 and plate I2, so as to approximate an entering curvaturebetween the ball bearing wheels and the curvature of the various wiresused. In such a case, the screw I5 is used to locate the plate I3 atapproximately the correct angle with plate I2. If a more accurateadjustment is required, screw I5 can be omitted, and the angle betweenplate I3 and plate I2 can be adjusted to any desired angle and then heldin position by tightening nut II. This may be necessary in cases wherethe temper of the wire, size of the coil, or' size of the wire, areconsiderably difierent from the usual wire used. The angle of the axisof plate I6 with respect to the axis of plate I2 must be adjusted ineach case so as to be just enough to remove the curvature from the wirecompletely and yet not give the wire a permanent curvature in theopposite direction. This is easily done as the wire through the variousball as indicated in Fig. 2', then pull on the end of the wire 4 untilabout one or two feet of wire extends from the rollers 33 and 34. Ifthis extending wire is curved in the direction of the curvature of thewire on the coil, the plate I6 should be further set over until thecorrect angle with respect to plate I2 is obtained; alternatively, ifthewire extending from beyond the ball bearing wheels 33 and 34 has acurvature in the opposite direction from the original curvature of thewire, sitely adjusted with respect to plate I 2. It is thus possible todetermine in this simple manner the correct angle necessary to produce awire having its curvature completely removed therefrom.

The foregoing description is given by way of illustration and not oflimitation and it is therefore my intention that the invention belimited only by the appended claims or their equivalents wherein I haveendeavored to claim broadly all inherent novelty.

I claim:

1. Device for removing curvature from a metallizing wire, feeding into ametal spray gun, said curvature being due to coiling of such wire, wflchcomprises means for rotatably supporting a coil of wire, a first set ofwire guide means comprising a multiple number of rotatable guide wheelsadapted and positioned to define a wire guide orifice, and at least onepair of rotatable guide wheels adapted and positioned to guide said wiretherebetween and, together with said orifice in a substantially fixedpath of travel in approximation of said curvature, and a second set ofwire guide means comprising at least two pairs of rotatable guide wheelsadapted, and positionedto further' guide said wire between the wheelrims of each pair in a substantially fixed path of travel in a countercurvature direction substantially sufficient to straighten said wire,each of said pairs of guide wheels defining a wire guide space, thecenters of all of said wire guide spaces being substantially in the sameplane, with the center of said orifice, said means for rotatablysupporting a coil of wire being adapted and positioned to permit feedingof said wire to and through said orifice substantially in said plane andin continuation of said curvature.

2. Device for removing curvature from a metallizing wire, feeding into ametal spray gun, said curvature being due to coiling of such wire, whichcomprises means for rotatably supporting a coil of wire, a centerportion, a first end portion adiustably connected to one end of saidcenter portion, a second end portion adjustably conwheels defining awire guide space, the centers of all of said wire guide spaces beingsubstantially in the same plane with the center of said orifice, saidmeans for rotatably supporting a coil of wire being adapted andpositioned to permit feeding of said wire to and through said orificesubstantially in said plane and in continuation of said curvature.

3. Device in accordance with claim 2 in which said first end portion andsaid center portion carry means to bring the same into substantiallyfixed predetermined location with respect to each other.

4. Device for removing curvature from a metallizing wire, feeding into ametal spray gun, said curvature being due to the coiling of such wirebeyond the limit of its elasticity, which comprises means for rotatablysupporting a coil of wire, a first wire guide means defining a fixedpath of travel for such wire, substantially the same as said curvatureand substantially in the plane of said curvature and of said coil, andpositioned with respect to said first mentioned means to receive saidwire from said coil substantially in continuation of said curvature, anda second wire guide and bending means defining a substantialnected tothe other end of said center portion, a

multiple number of rotatable guide wheels carried by said first endportion adjacent the free end thereof and positioned thereon to define awire guide orifice, at least one'pair of rotatable rim channeled guidewheels carried by said second end portion adjacent the free end thereof,at least two pair of rim channeled guide wheels carried by said centerportion, at least one near each end thereof, the pair of rim channeledguide wheels on said center portion nearest said first end portion andsaid orifice being positioned to guide said wire in a substantiallyfixed path of travel in approximate simulation of said curvature, thepair of rim channeled guide wheels on said center portion nearest saidsecond end portion and said pair of rim channeled guide wheels adjacentthe end of said second end portion being positioned to guide said wirein a substantially fixed path of travel in a counter curvature directionsubstantially sumcient to straighten said wire, each of said pairs ofrim channeled guide ly fixed continuation of said path of travel of suchwire in substantially the same plane in a counter-curvature directionand bending such wire sufilciently beyond its elastic limit to fixedlyremove said curvature from said wire.

5. Device for removing curvature from 9. metallizing wire, feeding intoa metal spray gun, said curvature being due to the coiling of such wirebeyond the limit of elasticity thereof which comprises means forrotatably supporting a coil of wire, a first multiple number of wireguide means, positioned to define a first multiple number of wire guidespaces having their centers substantially along a curved linesubstantially the same as said curvature, and substantially in the planethereof, and positioned with respect to said first mentioned means toreceive said wire from said coil substantially in continuation of saidcurvature, and a second multiple number of wire guide means positionedto define a second multiple number of wire guide spaces having theircenters in substantially the same plane substantially along a curvedline extending in a counter-curvature direction for reversely bendingsaid wire suf- Q ficiently beyond the elastic limit to fixedly removethe said curvature from said wire.

ARTHUR P. SHEPARD.

